Spend 1 minute straight at full Aggro.
Kill 50 enemies total in Back-to-Back.
Drag and heal your partner 25 times.
Continue playing to unlock this secret achievement.
Purchase 3 weapons.
Kill 250 enemies total using Assault Rifles.
Complete all missions as a Professional.
Complete all missions with the Partner AI.
Purchase the MP7, M134, DAO-X Protecta, MGL MK-X, and the M107 Light Fifty.
Purchase every mask variant.
Earn one million dollars in total over the course of campaign mode.
Kill 50 enemies total in Co-op Riot Shield.
Kill 5 enemies total using Co-op Snipe.
Kill 250 enemies total using Shotguns.
Kill 250 enemies total using Machine Guns.
Kill 150 enemies total using Handguns.
Kill 250 enemies total using SMGs.
Kill 100 enemies total using Sniper Rifles.
Kill 25 enemies total using RPGs.
Kill 50 enemies total using the Melee Attack.
Kill 25 Martyrs by shooting the Bomb Packs on their chests.
Kill 25 Heavy Armor enemies.
Finish playing a versus ranked match.
Complete 20 minor objectives in a ranked match.
Complete a ranked match without ever needing to be revived.
Earn one billion dollars in total in ranked matches.
Heal your partner for the first time. Training does not count.
Win a ranked match without purchasing any additional weapons.
Kill 75 enemies while in the stealth mode of Overkill.
Kill 100 enemies while in the power mode of Overkill.
Kill 30 enemies using the Riot Shield melee attack
Collect all of the information cases in the entire game.
Win every stage of a ranked three round SSC Challenge match
Destroy 500 barrels in ranked SSC Challenge matches
Win a ranked SSC Challenge match
Achieve 75% accuracy at the conclusion of a ranked three round SSC Challenge match
Buy the 'pack 8' gun pack in a multiplayer ranked match
Destroy 300 destructible objects in Mission 7,8
Kill Dalton in less than 40 seconds
Final blow to Dalton is a headshot with a pimped .44 MODEL 29 handgun
